YARN-9545. Create healthcheck REST endpoint for ATSv2. Contributed by Zoltan Siegl.

(cherry picked from commit f1d3a17d3e)

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-api/src/main/java/org/apache/hadoop/yarn/api/records/timeline/TimelineHealth.java

@@ -0,0 +1,82 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.yarn.api.records.timeline;
+
+
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+
+import javax.xml.bind.annotation.XmlAccessType;
+import javax.xml.bind.annotation.XmlAccessorType;
+import javax.xml.bind.annotation.XmlElement;
+import javax.xml.bind.annotation.XmlRootElement;
+
+/**
+ * This class holds health information for ATS.
+ */
+@XmlRootElement(name = "health")
+@XmlAccessorType(XmlAccessType.NONE)
+@InterfaceAudience.Public
+@InterfaceStability.Unstable
+public class TimelineHealth {
+
+  /**
+   * Timline health status.
+   *
+   * RUNNING - Service is up and running
+   * READER_CONNECTION_FAULURE - isConnectionAlive() of reader implementation
+   *    reported an error
+   */
+  public enum TimelineHealthStatus {
+    RUNNING,
+    READER_CONNECTION_FAILURE
+  }
+
+  private TimelineHealthStatus healthStatus;
+  private String diagnosticsInfo;
+
+  public TimelineHealth(TimelineHealthStatus healthy, String diagnosticsInfo) {
+    this.healthStatus = healthy;
+    this.diagnosticsInfo = diagnosticsInfo;
+  }
+
+  public TimelineHealth() {
+
+  }
+
+  @XmlElement(name = "healthStatus")
+  public TimelineHealthStatus getHealthStatus() {
+    return healthStatus;
+  }
+
+  @XmlElement(name = "diagnosticsInfo")
+  public String getDiagnosticsInfo() {
+    return diagnosticsInfo;
+  }
+
+
+  public void setHealthStatus(TimelineHealthStatus healthStatus) {
+    this.healthStatus = healthStatus;
+  }
+
+  public void setDiagnosticsInfo(String diagnosticsInfo) {
+    this.diagnosticsInfo = diagnosticsInfo;
+  }
+
+
+}

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-applications-catalog/hadoop-yarn-applications-catalog-webapp/node_modules/.bin/apidoc

@@ -0,0 +1 @@
+../../target/generated-sources/vendor/apidoc/bin/apidoc

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-applications-catalog/hadoop-yarn-applications-catalog-webapp/node_modules/.bin/markdown-it

@@ -0,0 +1 @@
+../../target/generated-sources/vendor/markdown-it/bin/markdown-it.js

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-applications-catalog/hadoop-yarn-applications-catalog-webapp/node_modules/.bin/r.js

@@ -0,0 +1 @@
+../../target/generated-sources/vendor/requirejs/bin/r.js

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-applications-catalog/hadoop-yarn-applications-catalog-webapp/node_modules/.bin/r_js

@@ -0,0 +1 @@
+../../target/generated-sources/vendor/requirejs/bin/r.js

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-applications-catalog/hadoop-yarn-applications-catalog-webapp/node_modules/.bin/semver

@@ -0,0 +1 @@
+../../target/generated-sources/vendor/semver/bin/semver

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-applications-catalog/hadoop-yarn-applications-catalog-webapp/node_modules/.bin/shjs

@@ -0,0 +1 @@
+../../target/generated-sources/vendor/shelljs/bin/shjs

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-applications/hadoop-yarn-applications-catalog/hadoop-yarn-applications-catalog-webapp/yarn.lock

@@ -0,0 +1,422 @@
+# THIS IS AN AUTOGENERATED FILE. DO NOT EDIT THIS FILE DIRECTLY.
+# yarn lockfile v1
+
+
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+  version "1.6.10"
+  resolved "https://registry.yarnpkg.com/angular-loader/-/angular-loader-1.6.10.tgz#5ab1995c65dd38640e6d9d738dbd85eddd5ec310"
+
+angular-mocks@~1.6.4:
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+  resolved "https://registry.yarnpkg.com/angular-mocks/-/angular-mocks-1.6.10.tgz#6a139e43c461d0c9a5a1acebc91e63db16031176"
+
+angular-route@~1.6.4:
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+  resolved "https://registry.yarnpkg.com/angular-route/-/angular-route-1.6.10.tgz#4247a32eab19495624623e96c1626dfba17ebf21"
+
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+  resolved "https://registry.yarnpkg.com/angular/-/angular-1.6.10.tgz#eed3080a34d29d0f681ff119b18ce294e3f74826"
+
+apidoc-core@~0.8.2:
+  version "0.8.3"
+  resolved "https://registry.yarnpkg.com/apidoc-core/-/apidoc-core-0.8.3.tgz#d9d63545829df250d2cca049683a87e775364b96"
+  dependencies:
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+    glob "^7.1.1"
+    iconv-lite "^0.4.17"
+    klaw-sync "^2.1.0"
+    lodash "~4.17.4"
+    semver "~5.3.0"
+
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+  resolved "https://registry.yarnpkg.com/apidoc/-/apidoc-0.17.7.tgz#a49090cbd8b3aa457bd054f00e0037e975fd3ee7"
+  dependencies:
+    apidoc-core "~0.8.2"
+    commander "^2.19.0"
+    fs-extra "^7.0.0"
+    lodash "^4.17.10"
+    markdown-it "^8.3.1"
+    winston "^3.0.0"
+
+argparse@^1.0.7:
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+  resolved "https://registry.yarnpkg.com/argparse/-/argparse-1.0.10.tgz#bcd6791ea5ae09725e17e5ad988134cd40b3d911"
+  dependencies:
+    sprintf-js "~1.0.2"
+
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+  resolved "https://registry.yarnpkg.com/async/-/async-2.6.2.tgz#18330ea7e6e313887f5d2f2a904bac6fe4dd5381"
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+    lodash "^4.17.11"
+
+balanced-match@^1.0.0:
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+  resolved "https://registry.yarnpkg.com/balanced-match/-/balanced-match-1.0.0.tgz#89b4d199ab2bee49de164ea02b89ce462d71b767"
+
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+
+sprintf-js@~1.0.2:
+  version "1.0.3"
+  resolved "https://registry.yarnpkg.com/sprintf-js/-/sprintf-js-1.0.3.tgz#04e6926f662895354f3dd015203633b857297e2c"
+
+stack-trace@0.0.x:
+  version "0.0.10"
+  resolved "https://registry.yarnpkg.com/stack-trace/-/stack-trace-0.0.10.tgz#547c70b347e8d32b4e108ea1a2a159e5fdde19c0"
+
+string_decoder@^1.1.1:
+  version "1.2.0"
+  resolved "https://registry.yarnpkg.com/string_decoder/-/string_decoder-1.2.0.tgz#fe86e738b19544afe70469243b2a1ee9240eae8d"
+  dependencies:
+    safe-buffer "~5.1.0"
+
+string_decoder@~1.1.1:
+  version "1.1.1"
+  resolved "https://registry.yarnpkg.com/string_decoder/-/string_decoder-1.1.1.tgz#9cf1611ba62685d7030ae9e4ba34149c3af03fc8"
+  dependencies:
+    safe-buffer "~5.1.0"
+
+text-hex@1.0.x:
+  version "1.0.0"
+  resolved "https://registry.yarnpkg.com/text-hex/-/text-hex-1.0.0.tgz#69dc9c1b17446ee79a92bf5b884bb4b9127506f5"
+
+triple-beam@^1.2.0, triple-beam@^1.3.0:
+  version "1.3.0"
+  resolved "https://registry.yarnpkg.com/triple-beam/-/triple-beam-1.3.0.tgz#a595214c7298db8339eeeee083e4d10bd8cb8dd9"
+
+uc.micro@^1.0.1, uc.micro@^1.0.5:
+  version "1.0.6"
+  resolved "https://registry.yarnpkg.com/uc.micro/-/uc.micro-1.0.6.tgz#9c411a802a409a91fc6cf74081baba34b24499ac"
+
+universalify@^0.1.0:
+  version "0.1.2"
+  resolved "https://registry.yarnpkg.com/universalify/-/universalify-0.1.2.tgz#b646f69be3942dabcecc9d6639c80dc105efaa66"
+
+util-deprecate@^1.0.1, util-deprecate@~1.0.1:
+  version "1.0.2"
+  resolved "https://registry.yarnpkg.com/util-deprecate/-/util-deprecate-1.0.2.tgz#450d4dc9fa70de732762fbd2d4a28981419a0ccf"
+
+winston-transport@^4.3.0:
+  version "4.3.0"
+  resolved "https://registry.yarnpkg.com/winston-transport/-/winston-transport-4.3.0.tgz#df68c0c202482c448d9b47313c07304c2d7c2c66"
+  dependencies:
+    readable-stream "^2.3.6"
+    triple-beam "^1.2.0"
+
+winston@^3.0.0:
+  version "3.2.1"
+  resolved "https://registry.yarnpkg.com/winston/-/winston-3.2.1.tgz#63061377976c73584028be2490a1846055f77f07"
+  dependencies:
+    async "^2.6.1"
+    diagnostics "^1.1.1"
+    is-stream "^1.1.0"
+    logform "^2.1.1"
+    one-time "0.0.4"
+    readable-stream "^3.1.1"
+    stack-trace "0.0.x"
+    triple-beam "^1.3.0"
+    winston-transport "^4.3.0"
+
+wrappy@1:
+  version "1.0.2"
+  resolved "https://registry.yarnpkg.com/wrappy/-/wrappy-1.0.2.tgz#b5243d8f3ec1aa35f1364605bc0d1036e30ab69f"

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice-hbase/hadoop-yarn-server-timelineservice-hbase-client/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/HBaseTimelineReaderImpl.java

@@ -29,6 +29,7 @@ import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hbase.client.Connection;
 import org.apache.hadoop.hbase.client.ConnectionFactory;
 import org.apache.hadoop.service.AbstractService;
+import org.apache.hadoop.yarn.api.records.timeline.TimelineHealth;
 import org.apache.hadoop.yarn.api.records.timelineservice.TimelineEntity;
 import org.apache.hadoop.yarn.api.records.timelineservice.TimelineEntityType;
 import org.apache.hadoop.yarn.conf.YarnConfiguration;
@@ -158,6 +159,18 @@ public class HBaseTimelineReaderImpl
     return reader.readEntityTypes(hbaseConf, conn);
   }
 
+  @Override
+  public TimelineHealth getHealthStatus() {
+    if (!this.isHBaseDown()) {
+      return new TimelineHealth(TimelineHealth.TimelineHealthStatus.RUNNING,
+          "");
+    } else {
+      return new TimelineHealth(
+          TimelineHealth.TimelineHealthStatus.READER_CONNECTION_FAILURE,
+          "HBase connection is down");
+    }
+  }
+
   protected static final TimelineEntityFilters MONITOR_FILTERS =
       new TimelineEntityFilters.Builder().entityLimit(1L).build();
   protected static final TimelineDataToRetrieve DATA_TO_RETRIEVE =

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/reader/TimelineReaderManager.java

@@ -26,6 +26,7 @@ import org.apache.hadoop.classification.InterfaceStability.Unstable;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.security.UserGroupInformation;
 import org.apache.hadoop.service.AbstractService;
+import org.apache.hadoop.yarn.api.records.timeline.TimelineHealth;
 import org.apache.hadoop.yarn.api.records.timelineservice.FlowActivityEntity;
 import org.apache.hadoop.yarn.api.records.timelineservice.FlowRunEntity;
 import org.apache.hadoop.yarn.api.records.timelineservice.TimelineEntity;
@@ -219,4 +220,13 @@ public class TimelineReaderManager extends AbstractService {
     }
     return callerUGI != null && adminACLsManager.isAdmin(callerUGI);
   }
+
+  /**
+   * Check if reader connection is alive.
+   *
+   * @return boolean True if reader connection is alive, false otherwise.
+   */
+  public TimelineHealth getHealthStatus() {
+    return reader.getHealthStatus();
+  }
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/reader/TimelineReaderWebServices.java

@@ -48,6 +48,7 @@ import org.apache.hadoop.http.JettyUtils;
 import org.apache.hadoop.security.UserGroupInformation;
 import org.apache.hadoop.util.Time;
 import org.apache.hadoop.yarn.api.records.timeline.TimelineAbout;
+import org.apache.hadoop.yarn.api.records.timeline.TimelineHealth;
 import org.apache.hadoop.yarn.api.records.timelineservice.FlowActivityEntity;
 import org.apache.hadoop.yarn.api.records.timelineservice.TimelineEntity;
 import org.apache.hadoop.yarn.api.records.timelineservice.TimelineEntityType;
@@ -215,6 +216,38 @@ public class TimelineReaderWebServices {
     return TimelineUtils.createTimelineAbout("Timeline Reader API");
   }
 
+  /**
+   * Health check REST end point.
+   *
+   * @param req Servlet request.
+   * @param res Servlet response.
+   *
+   * @return A {@link Response} object with HTTP status 200 OK if the service
+   *         is running.
+   *         Otherwise, a {@link Response} object with HTTP status 500 is
+   *         returned.
+   */
+  @GET
+  @Path("/health")
+  @Produces(MediaType.APPLICATION_JSON + "; " + JettyUtils.UTF_8)
+  public Response health(
+      @Context HttpServletRequest req,
+      @Context HttpServletResponse res
+  ) {
+    Response response;
+    TimelineHealth timelineHealth = this.getTimelineReaderManager().getHealthStatus();
+    if (timelineHealth.getHealthStatus()
+        .equals(TimelineHealth.TimelineHealthStatus.RUNNING)) {
+      response = Response.ok(timelineHealth).build();
+    } else {
+       LOG.info("Timeline services health check: timeline reader reported " +
+           "connection failure");
+       response = Response.serverError().entity(timelineHealth).build();
+    }
+
+    return response;
+  }
+
   /**
    * Return a single entity for a given entity type and UID which is a delimited
    * string containing clusterid, userid, flow name, flowrun id and app id.

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/FileSystemTimelineReaderImpl.java

@@ -42,6 +42,7 @@ import org.apache.commons.csv.CSVParser;
 import org.apache.commons.csv.CSVRecord;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.service.AbstractService;
+import org.apache.hadoop.yarn.api.records.timeline.TimelineHealth;
 import org.apache.hadoop.yarn.api.records.timelineservice.TimelineEntity;
 import org.apache.hadoop.yarn.api.records.timelineservice.TimelineEvent;
 import org.apache.hadoop.yarn.api.records.timelineservice.TimelineMetric;
@@ -429,4 +430,26 @@ public class FileSystemTimelineReaderImpl extends AbstractService
     }
     return result;
   }
+
+  @Override
+  public TimelineHealth getHealthStatus() {
+    try {
+      File file = new File(rootPath);
+      if (file.exists()) {
+        return new TimelineHealth(TimelineHealth.TimelineHealthStatus.RUNNING,
+            "");
+      } else {
+        return new TimelineHealth(
+          TimelineHealth.TimelineHealthStatus.READER_CONNECTION_FAILURE,
+            "Root path \"" + rootPath + "\" does not exist"
+          );
+      }
+    } catch (Exception e) {
+      return new TimelineHealth(
+          TimelineHealth.TimelineHealthStatus.READER_CONNECTION_FAILURE,
+          e.getMessage()
+          );
+    }
+
+  }
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/main/java/org/apache/hadoop/yarn/server/timelineservice/storage/TimelineReader.java

@@ -24,6 +24,7 @@ import java.util.Set;
 import org.apache.hadoop.classification.InterfaceAudience.Private;
 import org.apache.hadoop.classification.InterfaceStability.Unstable;
 import org.apache.hadoop.service.Service;
+import org.apache.hadoop.yarn.api.records.timeline.TimelineHealth;
 import org.apache.hadoop.yarn.api.records.timelineservice.TimelineEntity;
 import org.apache.hadoop.yarn.server.timelineservice.reader.TimelineDataToRetrieve;
 import org.apache.hadoop.yarn.server.timelineservice.reader.TimelineEntityFilters;
@@ -192,4 +193,11 @@ public interface TimelineReader extends Service {
    * storage.
    */
   Set<String> getEntityTypes(TimelineReaderContext context) throws IOException;
+
+  /**
+   * Check if reader connection is working properly.
+   *
+   * @return True if reader connection works as expected, false otherwise.
+   */
+  TimelineHealth getHealthStatus();
 }

hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-timelineservice/src/test/java/org/apache/hadoop/yarn/server/timelineservice/reader/TestTimelineReaderWebServices.java

@@ -37,6 +37,7 @@ import org.apache.commons.io.FileUtils;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.http.JettyUtils;
 import org.apache.hadoop.yarn.api.records.timeline.TimelineAbout;
+import org.apache.hadoop.yarn.api.records.timeline.TimelineHealth;
 import org.apache.hadoop.yarn.api.records.timelineservice.TimelineEntity;
 import org.apache.hadoop.yarn.api.records.timelineservice.TimelineEntityType;
 import org.apache.hadoop.yarn.conf.YarnConfiguration;
@@ -777,4 +778,22 @@ public class TestTimelineReaderWebServices {
       client.destroy();
     }
   }
+
+  @Test
+  public void testHealthCheck() throws Exception {
+    Client client = createClient();
+    try {
+      URI uri = URI.create("http://localhost:" + serverPort + "/ws/v2/"
+      + "timeline/health");
+      ClientResponse resp = getResponse(client, uri);
+      TimelineHealth timelineHealth =
+          resp.getEntity(new GenericType<TimelineHealth>() {
+          });
+      assertEquals(200, resp.getStatus());
+      assertEquals(TimelineHealth.TimelineHealthStatus.RUNNING,
+          timelineHealth.getHealthStatus());
+    } finally {
+      client.destroy();
+    }
+  }
 }